FIG. 1 illustrates a conventional door mechanism of a stock bin of a bread maker. The door mechanism includes two rotatable door panels 11, two electromagnets 12 respectively controlling rotation of the door panels 11, and two connectors 13 each of which interconnects one of the door panels 11 and a respective one of the electromagnets 12. When the electromagnets 12 are energized, the connectors 13 are actuated by the electromagnets 12 to respectively drive the door panels 11 to rotate to an open position. When the electromagnets 12 are de-energized, the door panels 11 rotate to a closed position. However, because the electromagnets 12 can generate heat which can weaken the magnetic force thereof, it is likely to occur that the torque for opening the door panels 11 will be insufficient. Hence, there is room for improvement of the conventional door mechanism of the bread maker.